February 27, 2017 Weather and Climate Report. Short-term Forecasting Not So Easy.

Written by Sig Silber

Last week NOAA indicated a very high level of confidence in their 6 to 10 Day and 8 to 14 day Forecast. We demurred. Not sure who will turn out to be correct but NOAA has lowered their level of confidence in what they now call Week One. (Last week this was called Week Two.)  When I saw the blocking pattern in Beringia it seemed to me that making a forecast would be challenging and the models forecasting the MJO were all over the place.

First some housekeeping information. For those who want the forecasts beyond three months, we recently reported on the February 16 NOAA 15-Month Forecast and compared the first nine months of the NOAA Outlook with that of JAMSTEC in a special Update that you can get to by clicking here. Remember if you leave this page to visit links provided in this article, you can return by hitting your “Back Arrow”, usually top left corner of your screen just to the left of the URL box. We will of course publish a new 15 Month Update Report shortly after NOAA issues their update on March 16, 2017. There was a Climate Conference sponsored by Los Alamos National Laboratories (LANL) February 5 – 10 in Santa Fe, New Mexico and I gave a presentation on the Climate of the Southwest on Southwest Climate on February 10 and this presentation has been converted into an article form which was published Tuesday night and can be viewed by clicking here. Many of the presentations are available to be viewed at this link. It is a work in progress so all the presentations where the authors have agreed to make them public are not yet uploaded to that website. My presentation (Presentation F7) now appears there.

Global Warming Creeps Forward

It remains to be determined if this is good or bad. It is clearly good for those who sell stuff for home gardeners and swimsuits. It is probably good for those who sell airconditioners. There may be losers. People  tend to not sort things out but have their own emotional responses to Warming. I think this weather column was correct when it concluded that the groundhog had blown it. One has to search higher Latitudes for signs of winter.

Not sure why I decided to present this tonight but I thought it was a very neat compilation of useful information. The full article can be found here.

I think the column headings need to be shifted over to the right just a bit. Have not had time to study it well enough to be sure or I would fix that for the author.

Also miscellaneous I came across this image in Slideplayer.com and believe I am free to use it.

I wish I had had this when I made my Southwest Climate Presentation. I wish I had this for every month. When I have more time I might be able to find the full presentation. But just January explains a lot about winter weather. We will come back to this in future issues of this report. But now lets get to the current situation.

A. Focus on Alaska and CONUS (all U.S. except Hawaii)

First Let us focus on the Current (Right Now to 5 Days Out) Weather Situation.

Water Vapor.

This view of the past 24 hours provides a lot of insight as to what is happening.

Below is the same graphic as above but without the animation to show the current situation with respect to water vapor imagery for North America. It also covers more of CONUS.

Looking at the current activity of the Jet Stream.

Not all weather is controlled by the Jet Stream (which is a high altitude phenomenon) but it does play a major role in steering storm systems especially in the winter The sub-Jetstream level intensity winds shown by the vectors in this graphic are also very important in understanding the impacts north and south of the Jet Stream which is the higher-speed part of the wind circulation and is shown in gray on this map. In some cases however a Low-Pressure System becomes separated or “cut off” from the Jet Stream. In that case it’s movements may be more difficult to predict until that disturbance is again recaptured by the Jet Stream. This usually is more significant for the lower half of CONUS with the cutoff lows being further south than the Jet Stream.

This graphic provides a good indication of where the moisture is. It is a bit different than just moisture imagery as it is quantitative.

60 Hour Forecast.

Here is a national animation of weather fronts and precipitation forecasts with four 6-hour projections of the conditions that will apply covering the next 24 hours and a second day of two 12-hour projections the second of which is the forecast for 48 hours out and to the extent it applies for 12 hours, this animation is intended to provide coverage out to 60 hours. Beyond 60 hours, additional maps are available at links provided below.

The explanation for the coding used in these maps, i.e. the full legend, can be found here although it includes some symbols that are no longer shown in the graphic because they are implemented by color coding.

U.S.  3 Day to  7 Day Forecasts

Below is a graphic which highlights the forecasted surface Highs and the Lows re air pressure on Day 3. The Day 6 forecast can be found here.

Now looking at the 5 Day Jet Stream Forecast

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Putting the Jet Stream into Motion and Looking Forward a Few Days Also

To see how the pattern is projected to evolve,  please click here. In addition to the shaded areas which show an interpretation of the Jet Stream, one can also see the wind vectors (arrows) at the 300 Mb level.

This longer animation shows how the jet stream is crossing the Pacific and when it reaches the U.S. West Coast is going every which way.

When we discuss the jet stream and for other reasons, we often discuss different layers of the atmosphere. These are expressed in terms of the atmospheric pressure above that layer. It is kind of counter-intuitive to me. The below table may help the reader translate air pressure to the usual altitude and temperature one might expect at that level of air pressure. It is just an approximation but useful.

Re the above, H8 is a frequently used abbreviation for the height of the 850 millibar level, H7 is the 700 mb level, H5 is the 500 mb level, H3 is the 300 mb level. So if you see those abbreviations in a weather forecast you will know what they are talking about.

Click here to gain access to a very flexible computer graphic. You can adjust what is being displayed by clicking on “earth” adjusting the parameters and then clicking again on “earth” to remove the menu. Right now it is set up to show the 500 hPa wind patterns which is the main way of looking at synoptic weather patterns. This amazing graphic covers North and South America. It could be included in the Worldwide weather forecast section of this report but it is useful here re understanding the wind circulation patterns.

You can enlarge the below daily (days 3 – 7) weather maps for CONUS by clicking on Day 3 or Day 4 or Day 5 or Day 6 or Day 7. These maps auto-update so whenever you click on them they will be forecast maps for the number of days in the future shown.

Here is the seven-day cumulative precipitation forecast. More information is available here.

The map below is the mid-atmosphere 7-Day chart+ rather than the surface highs and lows and weather features. In some cases it provides a clearer less confusing picture as it shows only the major pressure gradients. This graphic auto-updates so when you look at it you will see NOAA’s latest thinking. The speed at which these troughs and ridges travel across the nation will determine the timing of weather impacts. This graphic auto-updates I think every six hours and it changes a lot. Because “Thickness Lines” are shown by those green lines on this graphic, it is a good place to define “Thickness” and its uses. The 540 Level general signifies equal chances for snow at sea level locations. Remember that 540 relates to sea level.

 Four- Week Outlook

I am going to show the three-month FMA Outlook (for reference purposes), the Early Outlook for the single month of March,  the 6 – 10 Day and 8 – 14 Day Maps and the Week 3 –  4 Experimental Outlook. I use “EC” in my discussions although NOAA sometimes uses “EC” (Equal Chances) and sometimes uses “N” (Normal) to pretty much indicate the same thing although “N” may be more definitive.  

First – Temperature

Here is the Three-Month FMA Temperature Outlook issued on February 16, 2017:

Here is the Temperature Early Outlook for March issued on February 16, 2017

6 – 10 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on February 27 was 2 out of 5)

8 – 14 Day Temperature Outlook issued today (Note the NOAA Level of Confidence in the Forecast Released on February 27 was 2 out of 5) 

Looking further out.

Now – Precipitation

Here is the three-month MAM Precipitation Outlook issued on February 16, 2017

And here is the Early Precipitation Outlook for March issued on February 16, 2017

6 – 10 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on February 27 was 2 out of 5)

8 – 14 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on February 27 was 2 out of 5)

Looking further out.

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Here is the NOAA discussion released today February 27, 2017.

6-10 DAY OUTLOOK FOR MAR 05 – 09 2017

TODAY’S DYNAMICAL MODELS ARE IN FAIR AGREEMENT ON THE 500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. AN AMPLIFIED PATTERN IS PREDICTED OVER ALASKA AS A STRONG RIDGE IS FORECAST OVER THE WESTERN ALEUTIANS AND A DEEP TROUGH IS PREDICTED TO DOMINATE MUCH OF THE REMAINDER OF THE STATE. A LOWER AMPLITUDE PATTERN IS FORECAST FARTHER TO THE SOUTH OVER THE CONUS. RIDGING AND ABOVE NORMAL HEIGHTS ARE FORECAST OVER THE SOUTHWESTERN AND SOUTH-CENTRAL CONUS WHILE A RELATIVELY LOW AMPLITUDE TROUGH IS FORECAST FARTHER TO THE EAST OVER THE NORTHEASTERN CONUS. ENSEMBLE SPREAD IS RELATIVELY HIGH OVER MUCH OF THE CONUS INDICATING THAT THERE ARE SIGNIFICANT DIFFERENCES AMONG INDIVIDUAL ENSEMBLE MEMBERS IN RESOLVING SHORTWAVE FEATURES OVER MUCH OF THE COUNTRY. DUE, IN PART, TO THESE DIFFERENCES, THE ENSEMBLE MEAN SOLUTIONS WERE GIVEN THE MAJORITY OF THE WEIGHT IN TODAY’S 500-HPA MANUAL HEIGHT BLEND. THE GREATEST WEIGHT WAS GIVEN TO TODAY’S 0Z CANADIAN ENSEMBLE MEAN AS IT HAD THE HIGHEST ANALOG CORRELATION (WHICH MEASURES HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT HAVE OCCURRED IN THE PAST) AMONG TODAY’S ENSEMBLE MEAN SOLUTIONS. 

BELOW NORMAL TEMPERATURES ARE STRONGLY FAVORED FOR MUCH OF ALASKA DUE TO THE DEEP TROUGH PREDICTED TO DOMINATE THE STATE. ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES ARE ALSO INDICATED FOR THE NORTHWESTERN CONUS CONSISTENT WITH BIAS-CORRECTED DYNAMICAL MODEL GUIDANCE FROM THE GEFS, ECMWF, AND CANADIAN ENSEMBLES. CONVERSELY, RIDGING AND NEAR TO ABOVE NORMAL HEIGHTS FAVOR ABOVE NORMAL TEMPERATURES FOR THE SOUTHWESTERN AND CENTRAL CONUS. ABOVE NORMAL  TEMPERATURES ARE ALSO FAVORED FOR MUCH OF THE EASTERN CONUS (ALTHOUGH WITH LOWER PROBABILITIES) DUE TO ANTICIPATED MILDER THAN NORMAL AIR EARLY IN THE PERIOD. 

BELOW MEDIAN PRECIPITATION IS FAVORED FOR CENTRAL AND WESTERN ALASKA DUE TO THE STRONG TROUGH AND ASSOCIATED ANOMALOUS NORTHERLY MID LEVEL FLOW PREDICTED OVER THE STATE. ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE PANHANDLE DOWNSTREAM OF THE PREDICTED TROUGH AXIS. THERE ARE INCREASED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR THE NORTHWESTERN CONUS DUE TO THE POTENTIAL FOR ENHANCED PACIFIC FLOW. BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHWESTERN CONUS AND MUCH OF THE CENTRAL CONUS DUE TO PREDICTED RIDGING AND NEAR TO ABOVE NORMAL HEIGHTS. ABOVE MEDIAN PRECIPITATION IS WEAKLY FAVORED FOR THE GREAT LAKES REGION AND PARTS OF THE NORTHEAST IN ASSOCIATION WITH A PREDICTED TROUGH. ABOVE MEDIAN PRECIPITATION IS ALSO FAVORED FOR PORTIONS OF THE FLORIDA PENINSULA AND GULF COAST REGION UNDERNEATH PREDICTED MEAN EASTERLY LOW LEVEL FLOW. 

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO MODERATELY HIGH ENSEMBLE SPREAD OVER MUCH OF THE CONUS.

8-14 DAY OUTLOOK FOR MAR 07 – 13 2017 

DURING THE WEEK-2 PERIOD, AN AMPLIFIED 500-HPA FLOW PATTERN CONTINUES TO BE FORECAST FOR ALASKA. A RIDGE IS PREDICTED OVER THE WESTERN ALEUTIANS WHILE A STRONG TROUGH IS FORECAST DOWNSTREAM OVER CENTRAL, MAINLAND ALASKA. RIDGING AND ABOVE NORMAL HEIGHTS ARE FORECAST OVER MUCH OF THE WESTERN CONUS WHILE A TROUGH IS PREDICTED OVER THE NORTHEAST. ENSEMBLE SPREAD IS MODERATELY HIGH OVER MUCH OF THE FORECAST DOMAIN. AS A RESULT, THE OFFICIAL 500-HPA HEIGHT BLEND FOR THE WEEK-2 PERIOD IS BASED PRIMARILY ON THE ENSEMBLE MEAN SOLUTIONS.   

BELOW NORMAL TEMPERATURES ARE STRONGLY FAVORED FOR MOST OF ALASKA DUE TO THE DEEP TROUGH PREDICTED OVER THE STATE. THERE ARE ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR THE SOUTHWESTERN AND CENTRAL CONUS DUE TO PREDICTED RIDGING AND NEAR TO ABOVE NORMAL HEIGHTS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHEASTERN CONUS DUE TO A PREDICTED MEAN TROUGH. ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES ARE ALSO INDICATED FOR PARTS OF THE NORTHWESTERN CONUS CONSISTENT WITH BIAS CORRECTED DYNAMICAL MODEL GUIDANCE. 

BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHWESTERN CONUS EXTENDING TO MUCH OF THE CENTRAL CONUS DUE TO PREDICTED RIDGING AND ABOVE NORMAL HEIGHTS. ENHANCED PROBABILITIES OF BELOW MEDIAN PRECIPITATION ARE ALSO INDICATED FOR MUCH OF THE SOUTHEASTERN CONUS IN ASSOCIATION WITH PREDICTED MEAN SURFACE HIGH PRESSURE. THE POTENTIAL FOR RETURN FLOW AROUND THIS HIGH LEADS TO A SLIGHT ENHANCEMENT OF ABOVE MEDIAN PRECIPITATION PROBABILITIES FOR SOUTHERN TEXAS. NEAR TO ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE GREAT LAKES REGION AND PARTS OF THE NORTHEAST IN ASSOCIATION WITH A PREDICTED TROUGH AND CONSISTENT WITH NAEFS GUIDANCE. ENHANCED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION ARE ALSO INDICATED FOR THE ALASKA PANHANDLE EXTENDING TO THE NORTHWESTERN CONUS  AHEAD OF A TROUGH PREDICTED OVER THE GULF OF ALASKA. ANOMALOUS NORTHERLY MID LEVEL FLOW ASSOCIATED WITH THE STRONG TROUGH PREDICTED OVER ALASKA LEADS TO ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR WESTERN AND CENTRAL PORTIONS OF THE STATE. 

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE TO MODERATELY HIGH MODEL SPREAD OVER THE CONUS.

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON MARCH 16

Some might find this analysis click to read interesting as the organization which prepares it focuses on the Pacific Ocean and looks at things from a very detailed perspective and their analysis provides a lot of information on the history and evolution of ENSO events.

Analogs to the Outlook.

Now let us take a detailed look at the “Analogs” which NOAA provides related to the 5 day period centered on 3 days ago and the 7 day period centered on 4 days ago. “Analog” means that the weather pattern then resembles the recent weather pattern and was used in some way to predict the 6 – 14 day Outlook.

Here are today’s analogs in chronological order although this information is also available with the analog dates listed by the level of correlation. I find the chronological order easier for me to work with. There is a second set of analogs associated with the Outlook but I have not been regularly analyzing this second set of information. The first set which is what I am using today applies to the 5 and 7 day observed pattern prior to today. The second set, which I am not using, relates to the correlation of the forecasted outlook 6 – 10 days out with similar patterns that have occurred in the past during the dates covered by the 6 – 10 Day Outlook. The second set of analogs may also be useful information but they put the first set of analogs in the discussion with the second set available by a link so I am assuming that the first set of analogs is the most meaningful and I find it so.

(t) = a month where the Ocean Cycle Index has just changed or does change the following month.

One thing that jumped out at me right away was the spread among the analogs from February 7 to March 12 which is 33 days which is less tight than last week but the March 12 analog is an outlier. I have not calculated the centroid of this distribution which would be the better way to look at things but the midpoint, which is a lot easier to calculate, is about February 23. These analogs are centered on 3 days and 4 days ago (February 22 or February 23). So the analogs could be considered to be in sync with the calendar meaning that we will be getting weather that we would normally get for this time of the year. If you eliminate the March 12 Analog the spread  is only 16 days and the midpoint would be Feb 5 which would suggest an early Spring. I personally believe that is a better interpretation.

For more information on Analogs see discussion in the GEI Weather Page Glossary.

There is just one El Nino Analog and four ENSO Neutral Analogs and two La Nina analogs. Looks like the analogs are suggesting that ENSO Neutral Conditions now apply unlike last when the signal was clearly El Nino. The phases of the ocean cycles of the analogs point slightly to McCabe B and D which are opposites. Although these analogs are not highly reliable for making forecasts, when they are so opposite to the forecast its raises questions in my mind as to the appropriate level of confidence to have in the 6 to 14 day forecast but not necessarily the Experimental Week 3-4 Precipitation Outlook.The NOAA forecast is rated as 2 out of 5 so it is consistent with lack of clear cut signals from the analogs and also the major change from the prior week to this week.

The seminal work on the impact of the PDO and AMO on U.S. climate can be found here. Water Planners might usefully pay attention to the low-frequency cycles such as the AMO and the PDO as the media tends to focus on the current and short-term forecasts to the exclusion of what we can reasonably anticipate over multi-decadal periods of time. One of the major reasons that I write this weather and climate column is to encourage a more long-term and World view of weather.

You may have to squint but the drought probabilities are shown on the map and also indicated by the color coding with shades of red indicating higher than 25% of the years are drought years (25% or less of average precipitation for that area) and shades of blue indicating less than 25% of the years are drought years. Thus drought is defined as the condition that occurs 25% of the time and this ties in nicely with each of the four pairs of two phases of the AMO and PDO.

Historical Anomaly Analysis

When I see the same dates showing up often I find it interesting to consult this list.

Recent CONUS Weather

This is provided mainly to see the pattern in the weather that has occurred recently.

Here is the 30 Days ending February 18, 2017

And the 30 Days ending February 25, 2017

Here is a different view and I don’t believe  that I can get this for the entire U.S.

B. Beyond Alaska and CONUS Let’s Look at the World which of Course also includes Alaska and CONUS

Todays Forecast

Additional Maps showing different weather variables can be found here.

Near Term (Currently Set for Day 3 but the reader can change that)

World Weather Forecast produced by the Australian Bureau of Meteorology. Unfortunately I do not know how to extract the control panel and embed it into my report so that you could use the tool within my report. But if you visit it Click Here you will be able to use the tool to view temperature or many other things for THE WORLD. It can forecast out for a week. Pretty cool. Return to this report by using the “Back Arrow” usually found top left corner of your screen to the left of the URL Box. It may require hitting it a few times depending on how deep you are into the BOM tool.

Although I can not display the interactive control panel in my article, I can display any of the graphics it provides so below are the current worldwide precipitation and temperature forecasts for three days out. They will auto-update and be current for Day 3 whenever you view them. If you want the forecast for a different day Click Here

Precipitation

Temperature

Looking Out a Few Months

Here is the new precipitation forecast from Queensland Australia:

JAMSTEC Forecasts

JAMSTEC issued their ENSO forecasts and climate maps on February 14. We published a special Update Report on Saturday Night February 18 which can be accessed by clicking here. Remember if you leave this page to visit links provided in this article, you can return by hitting your “Back Arrow”, usually top left corner of your screen just to the left of the URL box. One can always find the latest JAMSTEC maps at this link. You will find additional maps that I do not general cover in my monthly Update Report.

Sea Surface Temperature (SST) Departures from Normal for this Time of the Year i.e. Anomalies

And when we look at the current Sea Surface anomalies below, we see a lot of them not just along the Equator related to ENSO. I have switched over to the weekly analysis. It is less visually interesting but probably more meaningful and the Daily has have some update issues. . .

Below I show the changes over the last four weeks in the Sea Surface Temperature (SST) anomalies.

Below is an analysis of projected tropical hazards and benefits over an approximately two-week period.

Now let us look at the Western Pacific in Motion.

C. Progress of ENSO

Starting with Surface Conditions.

TAO/TRITON GRAPHIC (a good way of viewing data related to the part of the Equator and the waters close to the Equator in the Eastern Pacific  where we monitor to determining the current phase of ENSO. It is probably not necessary to follow the discussion below, but here is a link to TAO/TRITON terminology.

And here is the current version of the TAO/TRITON Graphic. The top part shows the actual temperatures, the bottom part shows the anomalies i.e. the deviation from normal.

The below table which only looks at the Equator shows the extent of anomalies along the Equator. I had split the table to show warm, neutral, and cool anomalies. The top rows showed El Nino anomalies. When there were no more El Nino anomalies along the Equator, I eliminated those rows. NOW i AM PUTTING THEM BACK IN. The two rows just below that break point contribute to ENSO Neutral and after another break, the rows are associated with La Nina conditions. I have changed the reference date to May 23, 1016. I probably have more to do but one step at a time.

I calculate the current value of the ONI index (really the value of NINO 3.4 as the ONI is not reported as a daily value) each week using a method that I have devised. To refine my calculation, I have divided the 170W to 120W Nino 3.4 measuring area into five subregions (which I have designated from west to east as A through E) with a location bar shown under the TAO/TRITON Graphic). I use a rough estimation approach to integrate what I see below and record that in the table I have constructed. Then I take the average of the anomalies I estimated for each of the five subregions.

So as of Monday February 27, in the afternoon working from the February 26 TAO/TRITON report, this is what I calculated. [Although the TAO/TRITON Graphic appears to update once a day, in reality it updates more frequently.]

Sea Surface Temperature and Anomalies

It is the ocean surface that interacts with the atmosphere and causes convection and also the warming and cooling of the atmosphere. So we are interested in the actual ocean surface temperatures and the departure from seasonal normal temperatures which is called “departures” or “anomalies”. Since warm water facilitates evaporation which results in cloud convection, the pattern of SST anomalies suggests how the weather pattern east of the anomalies will be different than normal.

I had stopped showing the below graphic which is more focused on the Equator but looks down to 300 meters rather than just being the surface. But recently there has been sufficient change to warrant including this graphic. And now that we are back tracking a possible El Nino it is the graphic of choice.

Let us look in more detail at the Equatorial Water Temperatures.

We are now going to change the way we look at a three-dimensional view of the Equator and move from the surface view and an average of the subsurface heat content to a more detailed view from the surface down. Notice by the date of the graphic (dated February 22, 2017) that the lag in getting this information posted so the current situation may be a bit different than shown. The date shown is the midpoint of a five-day period with that date as the center of the five-day period.

Below is the pair of graphics that I regularly provide.

The bottom graphic shows the absolute values, the upper graphic shows anomalies compared to what one might expect at this time of the year in the various areas both 130E to 90W Longitude and from the surface down to 450 meters. At different times and today in particular, I have discussed the difference between the actual values and the deviation of the actual values from what is defined as current climatology (which adjusts every ten years except along the Equator where it is adjusted every five years) and how both measures are useful but for different purposes.

The bottom half of the graphic (Absolute Values which highlights the Thermocline) is now more useful as we track the transition to and ENSO Cool Event which may possibly become and El Nino.

Here are the above graphics as a time sequence animation. You may have to click on them to get the animation going.

The graphic which used to appear hear seems unnecessary now and was always redundant so I have dropped it for the time being.

And now Let us look at the Atmosphere.

Low-Level Wind Anomalies near the Equator

Here are the low-level wind anomalies.

And now the Outgoing Longwave Radiation Anomalies which tells us where convection has been taking place. 

And Now the Air Pressure which Shows up Mostly in an Index called the SOI.

This index provides an easy way to assess the location of and the relative strength of the Convection (Low Pressure) and the Subsidence (High Pressure) near the Equator. Experience shows that the extent to which the Atmospheric Air Pressure at Tahiti exceeds the Atmospheric Pressure at Darwin Australia when normalized is substantially correlated with the Precipitation Pattern of the entire World. At this point there seems to be no need to show the daily preliminary values of the SOI but we can work with the weekly values.

To some extent it is the change in the SOI that is of most importance. It had been increasing in September but now from October through January the SOI has stabilized in the Neutral Range.

The MJO or Madden Julian Oscillation is an important factor in regulating the SOI and Kelvin Waves and other tropical weather characteristics. More information on the MJO can be found here. Here is another good resource. January accelerated the decline of this near La Nina development and most likely February will also be unkind in the opposite way in terms of the MJO as it does not deplete the cool pool but stimulates Kelvin Waves. .

This Table is a first attempt at trying to related the MJO to ENSO

Forecasting the Evolution of ENSO

We now have both the February early-month report and the mid-month model-based report from CPC/IRI  There is  really no need to show both but I will for the time being do so simply to avoid having to explain the differences in the early versus mid-month report. But showing both the reader will hopefully become familiar with the differences between the two reports.

Here is the report from mid February.

Here is the discussion that was released with the IRI/CPC Report.

Note: The SST anomalies cited below refer to the OISSTv2 SST data set, and not ERSSTv4. OISSTv2 is often used for real-time analysis and model initialization, while ERSSTv4 is used for retrospective official ENSO diagnosis because it is more homogeneous over time, allowing for more accurate comparisons among ENSO events that are years apart. During ENSO events, OISSTv2 often shows stronger anomalies than ERSSTv4, and during very strong events the two datasets may differ by as much as 0.5 C. Additionally, the ERSSTv4 may tend to be cooler than OISSTv2, because ERSSTv4 is expressed relative to a base period that is updated every 5 years, while the base period of OISSTv2 is based on a slightly older period and does not account as much for the slow warming trend in the tropical Pacific SST.

Recent and Current Conditions

In January 2017, the NINO3.4 SST anomaly, which had been near or slightly cooler than -0.5 C since the middle of 2016 (making for a borderline or weak La Niña SST condition), warmed back to neutral. For January the SST anomaly was -0.32 C, and for Nov-Jan it was -0.43 C. The IRI’s definition of El Niño, like NOAA/Climate Prediction Center’s, requires that the SST anomaly in the Nino3.4 region (5S-5N; 170W-120W) exceed 0.5 C. Similarly, for La Niña, the anomaly must be -0.5 C or less. The climatological probabilities for La Niña, neutral, and El Niño conditions vary seasonally, and are shown in a table at the bottom of this page for each 3-month season. The most recent weekly anomaly in the Nino3.4 region was 0.1, at an ENSO-neutral level. The SST farther east has increased to above-average levels. Most of the pertinent atmospheric variables also returned to neutral patterns, with the exception of the convection anomalies in the central and western tropical Pacific, which continued to suggest a weak La Niña. The lower-level trade winds and upper level westerly winds have been largely near-average, and the Southern Oscillation Index (SOI) has been near-average during January and early February. Subsurface temperature anomalies across the eastern equatorial Pacific have increased to near-average. Overall, given the SST and the atmospheric conditions, the diagnosis of ENSO-neutral is clearly most appropriate.

Expected Conditions

What is the outlook for the ENSO status going forward? The most recent official diagnosis and outlook was issued one week ago in the NOAA/Climate Prediction Center ENSO Diagnostic Discussion, produced jointly by CPC and IRI; it stated that the ENSO conditions have returned to neutral during January, and that ENSO-neutral is the most likely condition through May 2017. The latest set of model ENSO predictions, from mid-February, now available in the IRI/CPC ENSO prediction plume, is discussed below. Those predictions suggest that the SST is most likely to be in the ENSO-neutral range from February-Apr season forward through most of the first half of 2017, but with increased uncertainty from around May onward, when El Niño development becomes a possibility.

As of mid-February, 96% of the dynamical or statistical models predicts neutral ENSO conditions for the initial Feb-Apr 2017 season, while 4% predicts El Niño conditions. At lead times of 3 or more months into the future, statistical and dynamical models that incorporate information about the ocean’s observed subsurface thermal structure generally exhibit higher predictive skill than those that do not. For the May-Jul 2017 season, among models that do use subsurface temperature information, no model predicts La Niña conditions, 61% predicts El Niño conditions, while 39% predicts neutral ENSO. For all model types, the probabilities for La Niña are 6% or less for for all predicted seasons from Feb-Apr through Oct-Dec 2017. The probability for El Niño conditions is near 5% for Feb-Apr and Mar-May, then rises to near 25% for Apr-Jun, and approximately 50% from May-Jul through the final season of Oct-Dec. Chances for neutral ENSO conditions exceeds 90% for Feb-Apr and Mar-May, is near 75% for Apr-Jun, and between approximately 40 to 55% from May-Jul through Oct-Dec.

Caution is advised in interpreting the distribution of model predictions as the actual probabilities. At longer leads, the skill of the models degrades, and skill uncertainty must be convolved with the uncertainties from initial conditions and differing model physics, leading to more climatological probabilities in the long-lead ENSO Outlook than might be suggested by the suite of models. Furthermore, the expected skill of one model versus another has not been established using uniform validation procedures, which may cause a difference in the true probability distribution from that taken verbatim from the raw model predictions.

An alternative way to assess the probabilities of the three possible ENSO conditions is more quantitatively precise and less vulnerable to sampling errors than the categorical tallying method used above. This alternative method uses the mean of the predictions of all models on the plume, equally weighted, and constructs a standard error function centered on that mean. The standard error is Gaussian in shape, and has its width determined by an estimate of overall expected model skill for the season of the year and the lead time. Higher skill results in a relatively narrower error distribution, while low skill results in an error distribution with width approaching that of the historical observed distribution. This method shows probabilities for La Niña at less than 10% from Feb-Apr through Jul-Sep 2017, increasing slightly thereafter, reaching nearly 20% by Oct-Dec. Probabilities for ENSO-neutral are near 95% for Feb-Apr 2017, falling steadily to 55% by May-Jul, and down to near 35% by the final Oct-Dec season. Probabilities for El Niño are less than 5% for Feb-Apr, rise to about 25% by Apr-Jun and to approximately 45-50% for Jun-Aug through the final season of Oct-Dec. A plot of the probabilities generated from this most recent IRI/CPC ENSO prediction plume using the multi-model mean and the Gaussian standard error method summarizes the model consensus out to about 10 months into the future. The same cautions mentioned above for the distributional count of model predictions apply to this Gaussian standard error method of inferring probabilities, due to differing model biases and skills. In particular, this approach considers only the mean of the predictions, and not the total range across the models, nor the ensemble range within individual models.

In summary, the probabilities derived from the models on the IRI/CPC plume describe, on average, a very high likelihood for neutral ENSO conditions for Feb-Apr. ENSO-neutral is predicted to remain the most likely of the three possibilities throughout around Jun-Aug, after which El Niño becomes more likely than neutral through the final season of Oct-Dec. Although most likely, the chances for El Niño only reaches near 50% during Jul-Sep through Oct-Dec. Chances for La Niña are below 10% through the first half of 2017, and only increase slightly later in the year, remaining less than 20% throughout. A caution regarding this latest set of model-based ENSO plume predictions, is that factors such as known specific model biases and recent changes that the models may have missed will be taken into account in the next official outlook to be generated and issued in early March by CPC and IRI, which will include some human judgment in combination with the model guidance.

Here is the earlier in the month February 9 Tea Leaves Report.

The official CPC/IRI ENSO probability forecast, based on a consensus of CPC and IRI forecasters. It is updated during the first half of the month, in association with the official CPC/IRI ENSO Diagnostic Discussion. It is based on observational and predictive information from early in the month and from the previous month. It uses human judgment in addition to model output, while the forecast shown in the Model-Based Probabilistic ENSO Forecast relies solely on model output. This is updated on the second Thursday of every month.

Here is the daily PDF and Spread Corrected version of the NOAA CFSv2 Forecast Model.

The full list of weekly values can be found here.

From Tropical Tidbits.com

The above is from a legacy “frozen” NOAA system meaning the software is maintained but not updated. It seems to show a cycle in the Nino 3.4 Index Values. I see that as I monitor the TAO/TRITON graphic. My best guess is that it is related to the MJO but it certainly is intriguing. I do not need to draw in the lines for you to see that the Nino 3.4 Index as reported by CDAS has moved above the 0C line and is now reporting a warm anomaly.

Forecasts from Other Meteorological Agencies.

Here is the Nino 3.4 report from the Australian BOM (it updates every two weeks)

Discussion (notice their threshold criteria are different from NOAA).

El Niño WATCH: likelihood of El Niño in 2017 increases

The El Niño-Southern Oscillation (ENSO) remains neutral. However, recent changes in both the tropical Pacific Ocean and atmosphere, and climate model outlooks surveyed by the Bureau, suggest the likelihood of El Niño forming in 2017 has risen. As a result, the Bureau’s ENSO Outlook status has been upgraded to El Niño WATCH, meaning the likelihood of El Niño forming in 2017 is approximately 50%.

All atmospheric and oceanic indicators of ENSO are currently within neutral thresholds. However, sea surface temperatures have been increasing in the eastern Pacific Ocean and are now warmer than average for the first time since June 2016, while the Southern Oscillation Index (SOI) has been trending downwards.

Seven of eight international models surveyed by the Bureau indicate steady warming in the central tropical Pacific Ocean over the next six months. Six models suggest El Niño thresholds may be reached by July 2017. However, some caution must be taken at this time of year, with lower model accuracy through the autumn months compared to other times of the year.

El Niño is often associated with below average winter–spring rainfall over eastern Australia and warmer than average winter–spring maximum temperatures over the southern half of Australia.

The Indian Ocean Dipole (IOD) has little influence on Australia from December to April. Current outlooks suggest a neutral IOD may persist until the end of autumn.

Here is the recently released JAMSTEC Nino 3.4 Forecast.

Based on the Nino 3.4 projection, JAMSTEC is saying the Cool Event did not meet the criteria to have been declared a La Nina as was done by NOAA: Nino 3.4 being colder than -0.5 and the duration of being under -0.5 was not sufficient  to qualify as a La Nina.

JAMSTEC is raising the possibility of an El Nino for the following winter. But it is too soon to make that prediction and the prior forecast last month suggested that such a warm event would be too short to qualify as an El Nino. That is not the case with the current forecast but forecasts in February are unreliable.

The Discussion that goes with their Nino 3.4 forecast has just been released. Notice the suggestion that we might be having a Pacific Climate Shift to PDO Positive.

Feb. 18, 2017
Prediction from 1st Feb., 2017

ENSO forecast:
The SINTEX-F now clearly predicts an El Niño event from this coming summer. This may suggest a decadal turnabout in the tropical Pacific climate condition to El Niño-like state after a long spell of La Niña-like state. If this happens, such natural climate variability may double the global warming impact as we observed during the period from 1976 through 1998.

Indian Ocean forecast:
Occurrence of a positive Indian Ocean Dipole is also clearly predicted; almost all ensemble members are suggesting the evolution in summer and the height in fall. We may observe co-occurrence of a positive Indian Ocean Dipole and an El Niño in the latter half of 2017; this is just as in 1997 and 2015.

Regional forecast:
On a seasonal scale, most part of the globe will experience a warmer-than-normal condition, while some parts of western Canada and northern Brazil will experience a colder-than-normal condition in the boreal spring. In the boreal summer, most parts of the globe will experience a hotter-than-normal condition. On the other hand, some parts of central Russia, northern China, and northern Australia will experience a cooler-than-normal condition.

According to the seasonally averaged rainfall prediction, a wetter-than-normal condition is predicted for eastern part of Brazil, northeastern part of China, and eastern part of southern Africa during the boreal spring, whereas most parts of southeastern China, Indonesia, and Europe will experience a drier condition during the boreal spring. In the boreal summer, most parts of Indonesia, western India, and Australia will experience a drier-than-normal condition, due to the El Niño and the positive Indian Ocean Dipole. Most parts of Japan will be in a warmer and wetter-than-normal condition in the boreal spring (except for less rain expected in March). In boreal summer, we expect a cooler (hotter)-than-normal condition in the northern (western) part. Since the Bonin high may not be matured in summer due to expected El Niño, we expect rather abnormal summer conditions particularly in the northern part. However, we also expect that the El Niño influences may be partly canceled mostly in the western part due to development of the positive Indian Ocean Dipole.

Indian Ocean IOD (It updates every two weeks)

The IOD Forecast is indirectly related to ENSO but in a complex way.

Discussion

Indian Ocean Dipole outlooks

The Indian Ocean Dipole (IOD) is neutral. The weekly index value to 26 February was +0.11 °C.

The influence of the IOD on Australian climate is weak during December to April. This is due to the monsoon trough shifting south over the tropical Indian Ocean and changing the overall wind circulation, which in turn prevents an IOD ocean temperature pattern from being able to form. Current outlooks suggest a neutral IOD for the end of autumn.

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D. Putting it all Together.

This Cool Event is over and NOAA using the “toe in the water test” has recognized and acknowledged that on February 9, 2017. At this time there is now some interest as to whether or not next Summer and Fall will be El Nino situations. The models are suggesting this as a possibility. But it is too soon to tell due to the Spring Predictability Barrier or SPB which was explained earlier.

Forecasting Beyond Five Years.

So in terms of long-term forecasting, none of this is very difficult to figure out actually if you are looking at say a five-year or longer forecast.

The research on Ocean Cycles is fairly conclusive and widely available to those who seek it out. I have provided a lot of information on this in prior weeks and all of that information is preserved in Part II of my report in the Section on Low Frequency Cycles 3. Low Frequency Cycles such as PDO, AMO, IOBD, EATS.   It includes decade by decade predictions through 2050. Predicting a particular year is far harder. Parts of that discussion are in the beginning  section of this week’s Report.

E. Relevant Recent Articles and Reports

Weather in the News

Nothing to report

Weather Research in the News

Nothing to report.

Global Warming in the News

More Records Broken

F. Table of Contents for Page II of this Report Which Provides a lot of Background Information on Weather and Climate Science  

The links below may take you directly to the set of information that you have selected but in some Internet Browsers it may first take you to the top of Page II where there is a TABLE OF CONTENTS and take a few extra seconds to get you to the specific section selected. If you do not feel like waiting, you can click a second time within the TABLE OF CONTENTS to get to the specific part of the webpage that interests you.

1. Very High Frequency (short-term) Cycles PNA, AO,NAO (but the AO and NAO may also have a low frequency component.)

2. Medium Frequency Cycles such as ENSO and IOD

3. Low Frequency Cycles such as PDO, AMO, IOBD, EATS.

4. Computer Models and Methodologies

5. Reserved for a Future Topic  (Possibly Predictable Economic Impacts)

G. Table of Contents of Contents for Page III of this Report  – Global Warming Which Some Call Climate Change.  

The links below may take you directly to the set of information that you have selected but in some Internet Browsers it may first take you to the top of Page III where there is a TABLE OF CONTENTS and take a few extra seconds to get you to the specific section selected. If you do not feel like waiting, you can click a second time within the TABLE OF CONTENTS to get to the specific part of the webpage that interests you.

1. Introduction

2. Climate Impacts of Global Warming

3. Economic Impacts of Global Warming

4. Reports from Around the World on Impacts of Global Warming

Useful Background Information

With respect to relating analog dates to ENSO Events, the following table might be useful. In most cases this table will allow the reader to draw appropriate conclusions from NOAA supplied analogs. If the analogs are not associated with an El Nino or La Nina they probably are not as easily interpreted. Remember, an analog is indicating a similarity to a weather pattern in the past. So if the analogs are not associated with a prior El Nino or prior La Nina the computer models are not likely to generate a forecast that is consistent with an El Nino or a La Nina.

ONI Recent History

The Nov/Dec/Jan preliminary has just come out as -0.7 making this Cool Event for the moment officially a La Nina. I think it is a National Disgrace. it may be worse than that as there can be nefarious motives for reporting false information on things that might impact commodity prices. It is time for NOAA to be audited. 

The full history of the ONI readings can be found here. The MEI index readings can be found here.